1. Field of the Invention
The present invention relates to a device to protect a reproduction of a disk, a method of protecting the reproduction of the disk, and a recording medium for the method and more particularly, to a device to protect a reproduction of a disk using a lead-in region of the disk, a method of protecting reproduction of the disk, and a recording medium for the method.
2. Description of the Related Art
“Parental control,” which has been mentioned regarding conventional DVD systems, makes it possible to automatically reproduce only images and sounds that are determined as appropriate to provide to viewers. Parental control is achieved by comparing a parental level of a disk with an upper limit of the parental level of a disk player. The parental control can be set up on every title or part of a title, i.e., on some scenes which are considered inappropriate or controversial. In this case, only scenes in a certain parental control block, within the parental level that is allowable, are sequentially reproduced.
FIG. 1 is a diagram showing a conventional parental lock function of a DVD 100. The DVD 100 has presentation data 104, such as audio data or video data, and navigation data 101 which controls the presentation data 104. The navigation data 101 has Parental_ID_Field 103 as a system parameter 102. A DVD reproducing unit 110 includes a navigation manager 111, which manages the navigation data 101 of the DVD 100, and a presentation engine 113, which displays the presentation data 104 of the DVD 100. The parental control to reproduce the DVD 100 is performed comparing the Parental_ID_Field 103 stored in the DVD 100 with Player_Parental_ID 112 included in the DVD reproducing unit 110. In other words, the DVD reproducing unit 110 checks if the Player_Parental_ID 112 matches with the Parental_ID field 130 of a PGC for playback, and if the Player_Parental_ID 112 and the Parental_ID field 130 do not match with each other, or if no valid Parental ID is specified, the DVD reproducing unit 110 prevents a reproduction of the DVD 100.
Such a parental lock function can be performed in the DVD reproducing unit 110 only when the disk 100 supports the same function. However, in conventional readable optical recording media, a reproduction prevention lock can be set up on a DVD player so that recording media can possibly be prevented from being reproduced in the DVD player according to a user's preference, even though the recording media do not support a parental lock function.